People who challenge a helmet fine in court often escape it. In NSW, the defence of necessity allows people to break a law to avoid more dire consequences. Bicycle helmets increase the risk of accident and injury. To avoid a higher risk of accident, cyclists can choose not to wear a helmet.

This might explain why the police rarely book cyclists for helmets in NSW. It is pointless harassment: most people give up cycling, those who prefer to keep riding can challenge the fine in court.